题目内容
下面各题怎样算简便就怎样算.
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考点:分数的四则混合运算,运算定律与简便运算
专题:运算顺序及法则,运算定律及简算
分析:(1)(2)把除法变为乘法,约分计算.
(3)把除法变为乘法,运用乘法分配律简算.
(4)中括号内的运用减法的性质简算.
(5)先算括号内的,然后从左往右依次计算.
(3)把除法变为乘法,运用乘法分配律简算.
(4)中括号内的运用减法的性质简算.
(5)先算括号内的,然后从左往右依次计算.
解答:
解:(1)
÷
÷
=
×
×
=
(2)
÷4×
=
×
×
=
(3)
÷
+
×
=
×
+
×
=(
+
)×
=1×
=
(4)
÷[
-(
-
)]
=
÷[
-
+
)]
=
÷
=
×
=
(5)
×(
+
)÷
=
×
×
=
3 |
8 |
9 |
4 |
5 |
6 |
=
3 |
8 |
4 |
9 |
6 |
5 |
=
1 |
5 |
(2)
3 |
4 |
8 |
9 |
=
3 |
4 |
1 |
4 |
8 |
9 |
=
1 |
6 |
(3)
4 |
15 |
9 |
5 |
11 |
15 |
5 |
9 |
=
4 |
15 |
5 |
9 |
11 |
15 |
5 |
9 |
=(
4 |
15 |
11 |
15 |
5 |
9 |
=1×
5 |
9 |
=
5 |
9 |
(4)
5 |
8 |
3 |
4 |
3 |
4 |
3 |
8 |
=
5 |
8 |
3 |
4 |
3 |
4 |
3 |
8 |
=
5 |
8 |
3 |
8 |
=
5 |
8 |
8 |
3 |
=
5 |
3 |
(5)
3 |
5 |
1 |
2 |
1 |
3 |
4 |
9 |
=
3 |
5 |
5 |
6 |
9 |
4 |
=
9 |
8 |
点评:考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律简便计算.
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